An Eye Implant Engineered From Proteins In Pigskin Restored Sight In 14 Blind People

According to a new study published in the journal Nature Biotechnology, researchers implanted corneas made from pig collagen to restore sight in 20 people who were blind or visually impaired. "Fourteen of the patients were blind before they received the implant, but two years after the procedure, they had regained some or all of their vision," notes NBC News. "Three had perfect vision after the surgery." From the report: The patients, in Iran and India, all suffered from keratoconus, a condition in which the protective outer layer of the eye progressively thins and bulges outward. "We were surprised with the degree of vision improvement," said Neil Lagali, a professor of experimental ophthalmology at Linkoping University in Sweden who co-authored the study. Not all patients experienced the same degree of improvement, however. The 12 Iranian patients wound up with an average visual acuity of 20/58 with glasses; functional vision is defined as 20/40 or better with lenses. Nonetheless, Dr. Marian Macsai, a clinical professor of ophthalmology at the University of Chicago who wasn't involved in the study, said the technology could be a game changer for those with keratoconus, which affects roughly 50 to 200 out of every 100,000 people. It might also have applications for other forms of corneal disease. To create the implant, Lagali and his team dissolved pig tissue to form a purified collagen solution. That was used to engineer a hydrogel that mimics the human cornea. Surgeons then made an incision in a patient's cornea for the hydrogel. "We insert our material into this pocket to thicken the cornea and to reshape it so that it can restore the cornea's function," Lagali said. Traditionally, human tissue is required for cornea transplants. But it's in short supply, because people must volunteer to donate it after they die. So, Lagali said, his team was looking for a low-cost, widely available substitute. "Collagen from pigskin is a byproduct from the food industry," he said. "This makes it broadly available and easier to procure." After two years, the patients' bodies hadn't rejected the implants, and they didn't have any inflammation or scarring. But any experimental medical procedure comes with risk. In this case, Soiberman said, a foreign molecule like collagen could induce an immune reaction. The researchers prescribed patients an eight-week course of immunosuppressive eyedrops to lower the risk, which is less than the amount given to people who receive cornea transplants from human tissue. In those cases, patients take immunosuppressive medicine for more than a year, Lagali said. "There's always a risk for rejection of the human donor tissue because it contains foreign cells," he said. "Our implant does not contain any cells ... so there's a minimal risk of rejection." The procedure itself was also quicker than traditional cornea transplants. The researchers said each operation took about 30 minutes, whereas transplants of human tissue can take a couple of hours. [...] It's not yet clear whether the surgery would work for patients who have other forms of corneal disease aside from keratoconus.

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